Q: We’re in the process of designing an add-on for our home and are trying to figure out what kind of windows we want. But there are so many windows to choose from, where do we start?
A: People in our showroom often ask the same question. While there are many aspects to consider when selecting a window, materials selection is often the most essential.
It’s common knowledge that the key component of windows is glass. Today, most glass used in windows is generic, produced by a handful of suppliers. In fact, most of the larger manufacturers buy from the same company, Cardinal. They not only make the glass substrate, but also apply the low-E, energy efficient coatings, and make the insulating units that allows the glass to act as insulation.
Cardinal and other companies make low-E coatings with varying performance levels suitable for different goals, such as meeting solar control requirements (e.g., reducing glare and heat gain) or adapting to different locations and climates. Most customers have some knowledge of glass coating. What often surprises them is the variety of materials that window frames can be made from.
Vinyl or UPVC : More than 70% of windows sold in North America are made of this material, which is cost-effective, energy efficient, durable and readily available. They come mostly in white and tan colors that can be painted on the exterior. Most manufacturers also offer a handful of standard colors. Additional colors and patterns can be achieved by applying foil (a thin acrylic wrap) to the frame — a rare process in the West Coast market that’s becoming increasingly popular.
Composite materials: These frames are surging in popularity. Resin materials are reinforced with fibers to add structural integrity and rigidity — it’s common to use glass and wood fibers to add strength. These materials can be 4–10 times stronger than simple vinyl windows; this means they can be thinner and less bulky, resulting in narrower sight lines that emphasize the glass. This strength also means the frames are less prone to expansion and contraction so paint (or a colored foil or cap stock) can be applied on both exterior and interior sides. Using dark colors on the interior is fashionable.
Aluminum: Demand for frames of this type has grown in recent years. These products, with anodized or painted finishes, are strong, often feature clean sharp lines, and can span large openings. In most markets, a thermally improved product is required (a thermal barrier of a less conductive material is inserted into the frame to lower heat and cold transfer). Aluminum products are considerably more expensive to manufacture and often require field installation due to their sizes and configurations.
Wood: Traditional wood windows are still very popular, especially for higher-end homes. Because of their performance, aesthetic value and versatility, they can provide a distinct design element to a home. Whether painted or stained, the wood window is something to look at, not just through. Usually, today’s wood frame will have an aluminum (or sometimes composite) exterior that can be painted in a variety of colors. Common interior wood types are pine or alder (especially when painted), Douglas fir (which is exceptionally strong and beautiful when stained), mahogany, oak and cherry. With high-quality wood window manufacturers, the range of materials, for form and function, is vast.
Steel: Steel is quickly gaining market traction. At the higher end of the cost spectrum, steel offers a unique look, structural integrity and capacity for very large windows. Steel windows can be configured in unique and compelling styles, while their narrow frame profiles maximize the glass’s prominence. There are many steel window fabricators that purchase the same lineal parts and cut, weld and finish them into their own brand, but they’re essentially the same window made by different companies. Finishes can range from standard black paint to textured coatings and bronze finishes that patina with age. Steel windows may stretch a company’s limited capacities or be imported, resulting in lead times as long as six months, so you’ll need to start early when selecting steel. Also, these systems often require field installation and site glazing, making them more expensive.
Bronze and imported materials: Speaking of bronze and importing, at the top of the pyramid is extruded bronze framed windows. These can be built in very large sizes, offer meticulous performance (like aluminum and steel, they incorporate thermal barriers) and are visually stunning. Imported from Europe, these products often utilize European glass, offering larger standard sizes, clearer glass by default, and oftentimes, heat strengthened and laminated products as a baseline.
Within each of these material categories there are a variety of manufacturers with specific features and benefits, and varied price points based on quality, fit and finish. Not all vinyl windows offer the same features, and the same goes for wood, aluminum steel or bronze. But once you have a sense for the materials above, you can narrow down manufacturers, distributors and installers to best meet your needs.
Rick Locke is the owner of Windows, Doors & More, a member of the Master Builders Association of King and Snohomish Counties (MBAKS). If you have a home improvement, remodeling or residential homebuilding question you’d like answered by one of MBAKS’s more than 2,700 members, write to firstname.lastname@example.org.